1. Field of the Invention
This invention relates to image and video processing. More particularly, this invention relates to image and video processing systems and methods that use texture replacement in encoding and decoding.
2. Description of Related Art
Increased popularity of movie-on-demand (MoD) and near movie-on-demand (NMoD) services, which allow the user to watch any movie at any time and make use of VCR-like functionalities, makes them important applications of movie coding. The success of MoD and NMoD in movie production, distribution, and consumer markets depends, however, on both the efficient transmission of encoded movies and the obtaining of very high quality decoded images (including, but not limited to, pictures or movie frames). The economical and technical challenges of this task are considerable. For commercial viability, MoD and NMoD service pricing must compete with existing movie rental pricing. The cost of MoD delivery services is often prohibitive because of the need to reserve a dedicated channel at a video server for each user and the need for large bandwidth to handle the compressed high quality movie sequences.
To address the need to reserve a dedicated channel for each user, NMoD systems use broadcast or multicast technologies to enable multiple users to share a single video channel. This approach, however, results in limited movie selections, fixed playback schedules, and limited or no interactive control.
To address the need for large bandwidth, movies may be transmitted over existing higher bandwidth networks, such as Digital Subscriber Lines (DSL). This approach, however, results in limited bandwidth because a DSL-based technology, such as Asynchonous DSL (ADSL), limits transmission to a bit rate of approximately 500 kbits/second for 95% of the existing loops and therefore requires that compressed movie sequences be transmitted at lower bit rates to accommodate the bandwidths of most ADSL users.
State-of-art video coding systems that are compliant with existing MPEG and ITU standards can provide bit rates of hundreds of kbits/second in the compressed video streams. However, providing such bit rates comes at a cost of compromising the visual quality of the decoded movies. For example, encoding an original sequence of the movie entitled “6 DAYS AND 7 NIGHTS” using the H.26L codec, which is an emerging standard and an offspring of the ITU H.263 family of low bit rate standards, results in a bit rate of the compressed movie sequence being equal to about 242 kbits/second. However, the decoded frame of the movie sequence exhibits artifacts, as compared to the original frame, that are particularly visible in large textured areas. Accordingly, the visual quality of such a decoded sequence would not be acceptable for entertainment MoD or NMoD services.